IELTS Academic Reading Practice Test 3

Until the middle of the nineteenth century, time was a local matter. Each town set its clocks by the sun, so noon in one place arrived several minutes before noon in a town fifty miles to the east. Nobody found this inconvenient, because nobody needed to coordinate anything across that distance faster than a horse could travel. Local time was not an approximation of a correct time; it was simply what time was.

The railway destroyed that arrangement, and it did so through timetables rather than through speed. A train leaving one city and arriving in another required a single agreed schedule, and a schedule written in local times was not merely awkward but dangerous. Two trains sharing a single track and running to clocks that disagreed by four minutes could occupy the same rails at the same moment. Several early collisions were attributed directly to this, and it was the railway companies, not governments, that acted first.

British railways adopted a single standard, taken from the Greenwich observatory and distributed along the telegraph lines that ran beside the tracks. For some decades a curious hybrid persisted: public clocks in provincial towns carried two minute hands, one for local time and one for railway time. The town of Bristol kept both until the 1850s. Legal recognition lagged far behind practice — Britain did not make Greenwich time the legal standard until 1880, by which time the railways had used it for a generation.

Extending the idea worldwide required an agreement no single company could impose. The International Meridian Conference, held in Washington in 1884, invited delegates from twenty-five nations to select a common prime meridian. Greenwich was chosen largely on grounds of usage rather than principle: a substantial majority of the world's shipping already carried charts calculated from it, and changing the charts would have been expensive. France abstained and continued to reckon from Paris for a further twenty-seven years.

Adoption within countries was often slower and more contested than the conference suggested. In the United States, the railways introduced four standard zones in 1883, a year before the conference and eighteen years before Congress recognised them. Local resistance was real and articulate: a standard noon that did not match the sun overhead was described in several newspapers as an offence against nature, and some cities kept municipal time in deliberate defiance for years.

What the episode illustrates is how a technical standard becomes invisible. Time zones now feel like a feature of geography rather than a nineteenth-century administrative decision, and the arbitrariness has been forgotten so completely that the boundaries look natural. They are not: they bend around borders, cross oceans in straight lines drawn by treaty, and in a few places are offset by three-quarters of an hour for reasons that are entirely political.